Retention clip for concrete slab key joint forming strips

ABSTRACT

A wire-like spring clip and clip installing tool for clamping a retaining stake to a key joint forming strip for concrete slabs. The clip has a back portion transversely disposed against the retaining stake, and two prong-like arm portions extending under the lower edge of the forming strip and projecting upwardly against the back of the forming strip. The pring-like arm portions are spring biased to direct a compressing force in cooperation with the straight back portion, thereby firmly clamping the retaining stake against the forming strip. The installing tool which operates as a lever to facilitate installation of the clip on the retaining stake and forming strip comprises a flat rigid shank with a notched end for temporarily holding the clip for installation.

United States Patent [191 Hunter 1 May 29, 1973 RETENTION CLIP FOR CONCRETE SLAB KEY JOINT FORMING STRIPS [75] Inventor: Phillip S. Hunter, Castro Valley,

[58] Field a Search... 287/l89 .35, 20.92 R, 287/2092 c; 49, so, s1, 54 B; 24/261 R, 81 0, 84 c, 81 CR; 94/8, 17, 5 1

[56] References Cited UNITED STATES PATENTS 89,966 5/1869 Bailey ..24/261R 2,375,374 5/1945 Lepp ..24/s1c 2,523,785

9 1950 Sereno ..24/8l CR Harding ..287/l 89.35 X

Primary ExaminerDavid J. Williamowsky Assistant Examiner'-Wayne L. Shedd Attorney-Naylor & Neal [57] ABSTRACT A wire-like spring clip and clip installing tool for clamping a retaining stake to a key joint forming strip for concrete slabs. The clip has a back portion transversely disposed against the retaining stake, and two prong-like arm portions extending under the lower edge of the forming strip and projecting upwardly against the back of the forming strip. The pring-like arm portions are spring biased to direct a compressing force in cooperation with the straight back portion, thereby firmly clamping the retaining stake against the forming strip: The installing tool which operates as a lever to facilitate installation of the clip on the retaining stake and forming strip comprises a flat rigid shank with a notched end for temporarily holding the clip fo installation.

2 Claims, 7 Drawing Figures m'zageww' Patented May 29, 1973 FIE-.2

'INVENTOR. PHILLIP 5. HUNTER M f M ATTORNEV5 FIE-l- RETENTION CLIP FOR CONCRETE SLAB KEY JOINT FORMING STRIPS This application is a continuation of application Ser. No. 85 l ,994, filed Aug. 21, 1969, and now abandoned.

BACKGROUND OF THE INVENTION In the construction of poured concrete slabs, it has been found that divider strips should be placed at discrete intervalsto permit expansion and contraction of the hardened slabs with changes of temperature. To prevent vertical displacement of the slabs with respect to each other, the divider strip is fashioned into a key joint forming strip to provide for interlocking of adjacent slabs. For purposes of thisdisclosure the forming strip may be as described in. US. Pat. No. 3,288,042 entitled CONCRETE SLAB KEY JOINT FORMING STRIP.

The divider strip of the aforementioned patent is adapted to be suspended on suitable placed vertical retaining stakes driven into the ground to a predetermined level. The top of the stakes fit into a channelshaped recess or socket formed by a folded upper edge of the forming strip. The retaining stakes may be secured at the top by crimping an edge 'or lip of the forming strip into an adjacent aperture in the top of the stakes. However, when secured solely at the top of the stakes, the forming strip has a tendency to swing or lift when concrete is poured against the strip.

SUMMARY or THE INVENTION The present invention comprises a wire-like spring clip which clamps the thin, flat, lower edge of the form ing strip to the retaining stake, thus firmlysecuringthe stake to the forming strip at two separate locations. The clip thereby prevents any dislocation 'of the forming strip during pouring of the concrete.

To facilitate installationof'the clips, an installing tool has been devised. The installing tool preferably comprises a flat metal shank with two cornernotches which hold the clip at the end ofthe tool. Utilizing the leverage of the tool, the clip may be snapped onto the stake and forming strip.

BRIEF DESCRIPTION OF THE DRAWING tool.

FIG. 7 is an enlarged, partial planview ofthe clip and installing tool.

PREFERRED EMBODIMENT Referring to FIG. 1, thespring is designated 10 and is illustrated clamping a retaining stake 'l-2 to a forming strip 14. The retaining stake 12 is embeddedin a prepared subgrade l6. and supports the formingstrip 14 prior to pouring concrete. For added strength-to the concrete, reinforcing rods, exemplar 18-, maybe inserted throughholes (exemplardesignated by'nume'ral 19 in FIG. 2) in the forming strip 14, joining separate portions of a concrete slab 20. Concrete may be poured on either side of the forming strip 14 without causing the strip to swing or float upward which, without the clip, might otherwise result during pouring.

Turning to FIG. 2, the particular structural formation of the clip can be observed. The wire-like clip is comprised of a substantially. straight back portion 10a and two prong-like arm portions 10b which extend downwardly from the back portion 10a, loop and project upwardly in a parallel manner. The ends of the prong-like arm portions 10b, designated 10c, are bent slightly away from the back portion 100 to enable the clip to be installed without snagging on the forming strip 14.

In FIG. 3, the spring clip 10 is illustrated in its clamping position holding the retaining stake l2 firmly against the thin, flat, lower edge 22 of the forming strip 14. The upper edge 24 of the forming strip 14 is folded over and formed into a substantially inverted Y-shaped section defining a channel-shaped recess 26 into which the top of the stake 12 is inserted. The stake 12 is provided with a semicircular aperture 28 into which the lip 30 on the upper edge of the forming strip may be crimped as illustrated in FIG. 3. In this manner the stake 12 is held firmly against the forming strip at two separate, locations and will not become dislocated during concrete pouring.

clip creates a condition in which there results a single point of contact for each prong-like arm portion against the back 14a of the forming strip. The two contact points of the prong and the contact point of the straight back portion 10a transversely disposed against the retaining stake define a plane perpendicular to the stake for an effective opposed clamping action.

FIGS. 6 and 7 illustrate the clip and an installing tool 32 which has been devised to facilitate installation of the clip on the stake and strip.

The installing tool 32 comprises a flat rigid shank the end 34 of the tool with the ends of the two prong-like arm portions of the clip pointing upwardly-as shown in FIG. 6. With the clip so positioned, it is installed by first placing the curved end 34 of the installing tool 32 perpendicularly against the curved stake 12 below the lower edge 22 of the forming strip 14-and then sliding the end of the tool up the stake. The clip is thusforced to snap over the lower edge 22 of the forming strip 14 and into place. The tool is then twisted slightly todisengagethe tool from the clip.

As can be seen in FIG. 6, opposite the curved end, the tool is fabricated with a broad notched end 40 having an extension 42 at each corner of the tool. The notched end40provides a convenient tool for straightening any clip which may have become slightly disoriented when disengaging the tool from the clip. The notched end 40 is simply placed against the stake with the two extensions straddling the stakes edge. An up:

ward movement against the clip will adjust the clip to a proper seating. a

The notched end 40 may also be used to disengage the clip from the stake and strip if desired. For this operation the notched end 40 is placed against the stake just above the clip at an acute angle from the top of the stake. By pushing the end downward the clip will be disengaged from the forming strip 14 and retaining stake 12.

While the clip has been illustrated and described for use with a stake having an aperture into which the strip may be crimped for retention purposes, it should be understood that the clip is not limited to such use. Under most circumstances it will be found that the clip retains the stake against the strip with sufficient force that the crimping action is not necessary.

I claim:

1. In the combination comprising:

a. a concrete key joint forming strip of the type having suspension means on the upper portion and a free lower edge; and,

b. a generally vertically disposed stake having the upper end thereof received within the inverted channel-shaped upper portion of the strip to effect support of the strip in a condition wherein the lower edge of the strip rests against the stake;

the improvement comprising a spring clip for clamping the lower edge of the strip to the stake, said clip having a back portion which transversely disposes against the stake for contact therewith, and two pronglike arm portions which extend downwardly from the back portion and around the edges of the stake, loop under the lower edge of the forming strip, and extend upwardly into engagement with the forming strip, said arm portions being bent to form sections which extend into spring biased clamping engagement with the strip, said sections and said back portion clamping the stake and forming strip therebetween.

2. In the combination comprising:

a. a concrete key joint forming strip of the type having an inverted channel-shaped upper portion and a free lower edge; and,

b. a generally vertically disposed stake having the upper end thereof received within the inverted channel-shaped upper portion of the strip to effect support of the strip in a condition wherein the lower edge of the strip rests against the stake;

the improvement comprising a spring clip for clamping the lower edge of the strip to the stake, said clip having a back portion which transversely disposes against the stake in point contact therewith, and two pronglike arm portions which extend downwardly from the back portion and around the edges of the stake, loop under the lower edge of the forming strip, and extend upwardly into engagement with the forming strip; said arm portions being spring biased to force the forming strip against the stake and having ends which are bent away from the lower edge of the forming strip such that the upward extension of each arm portion has point contact against the forming strip, said points of contact of the arm portions and the back portion defining a plane extending transversely to the stake.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,736,013 Dated May 19.73

Inventor) Phillip S. Hunter It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, line 23, after "portion" insert for receiving the upper end of a stake V Column 3, lines 26 and '27, delete "inverted channel shaped" and substitute therefor suspension means on the Column 4, line 11, delete "an inverted channel-shaped" and substitute therefor suspension means on the Column 4, line 11 after "portion" insert for receiving the upper end of a stake Column 4, lines 14 and 15, delete "inverted channel-shaped" and substitute therefor suspension means-on the v.

Signed and Scaled this Eleventh Day Of January 1977 [SEAL] Arrest:

RUTH c. MASON c. MARSHALL DANN Arresting Officer Commissioner oflatents and Trademarks 

1. In the combination comprising: a. a concrete key joint forming strip of the type having suspension means on the upper portion and a free lower edge; and, b. a generally vertically disposed stake having the upper end thereof received within the inverted channel-shaped upper portion of the strip to effect support of the strip in a condition wherein the lower edge of the strip rests against the stake; the improvement comprising a spring clip for clamping the lower edge of the strip to the stake, said clip having a back portion which transversely disposes against the stake for contact therewith, and two pronglike arm portions which extend downwardly from the back portion and around the edges of the stake, loop under the lower edge of the forming strip, and extend upwardly into engagement with the forming strip, said arm portions being bent to form sections which extend into spring biased clamping engagement with the strip, said sections and said back portion clamping the stake and forming strip therebetween.
 2. In the combination comprising: a. a concrete key joint forming strip of the type having suspension means on the upper portion for receiving the upper end of a stake and a free lower edge; and, b. a generally vertically disposed stake having the upper end thereof received within the suspension means on the upper portion of the strip to effect support of the strip in a condition wherein the lower edge of the strip rests against the stake; the improvement comprising a spring clip for clamping the lower edge of the strip to the stake, said clip having a back portion which transversely disposes against the stake in point contact therewith, and two pronglike arm portions which extend downwardly from the back portion and around the edges of the stake, loop under the lower edge of the forming strip, and extend upwardly into engagement with the forming strip; said arm portions being spring biased to force the forming strip against the stake and having ends which are bent away from the lower edge of the forming strip such that the upward extension of each arm portion has point contact against the forming strip, said points of contact of the arm portions and the back portion defining a plane extending transversely to the stake. 